<?php
/**
 * Created by PhpStorm.
 * User: Administrator
 * Date: 2018/10/22
 * Time: 11:01
 */

namespace app\qgroup\service;


use app\common\service\BaseService;
use think\Exception;

class CodeFactory extends BaseService
{
    protected static $cf;
    public static function getInstance()
    {
        if (empty(self::$cf)){
            self::$cf = new CodeFactory();
        }
        return self::$cf;
    }
    /**
     * 加密
     * @param $arg string
     * @return bool|string
     */
    public function getNewCode($arg)
    {
        try {
            if (is_string($arg)) {
                return $this->ncrypt($arg, 'vovoqi');
            } else {
                return false;
            }
        }catch (Exception $exception){
            return $this->getNewCode($arg);
        }
    }

    /**
     * 解密
     * @param $arg string
     * @return string
     */
    public function getDecCode($arg)
    {
        try {
            if (is_string($arg) && !empty($arg)) {
                return $this->decrypt($arg, 'vovoqi');
            }
        }catch (Exception $exception){
            return $this->getDecCode($arg);
        }
    }

    /**
     * 加密
     * @param $txt string
     * @param $key string
     * @return string
     */
    protected function ncrypt($txt, $key)
    {
        $chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
        $ikey = "-x6g6ZWm2G9g_vr0Bo.pOq3kRIxsZ6rm";
        $nh1 = rand(0, 64);
        $nh2 = rand(0, 64);
        $nh3 = rand(0, 64);
        $ch1 = $chars{$nh1};
        $ch2 = $chars{$nh2};
        $ch3 = $chars{$nh3};
        $nhnum = $nh1 + $nh2 + $nh3;
        $knum = 0;
        $i = 0;
        while (isset($key{$i})) $knum += ord($key{$i++});
        $mdKey = substr(md5(md5(md5($key . $ch1) . $ch2 . $ikey) . $ch3), $nhnum % 8, $knum % 8 + 16);
        $txt = base64_encode($txt);
        $txt = str_replace(array('+', '/', '='), array('-', '_', '.'), $txt);
        $tmp = '';
        $j = 0;
        $k = 0;
        $tlen = strlen($txt);
        $klen = strlen($mdKey);
        for ($i = 0; $i < $tlen; $i++) {
            $k = $k == $klen ? 0 : $k;
            $j = ($nhnum + strpos($chars, $txt{$i}) + ord($mdKey{$k++})) % 63;
            $tmp .= $chars{$j};
        }

        $tmplen = strlen($tmp);
        $tmp = substr_replace($tmp, $ch3, $nh2 % ++$tmplen, 0);
        $tmp = substr_replace($tmp, $ch2, $nh1 % ++$tmplen, 0);
        $tmp = substr_replace($tmp, $ch1, $knum % ++$tmplen, 0);
        return $tmp;
    }

    /**
     * 解密
     * @param $txt string
     * @param $key string
     * @return string
     */
    protected function decrypt($txt, $key)
    {
        $chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
        $ikey = "-x6g6ZWm2G9g_vr0Bo.pOq3kRIxsZ6rm";
        $knum = 0;
        $i = 0;
        $tlen = strlen($txt);
        while (isset($key{$i})) $knum += ord($key{$i++});
        $ch1 = $txt{$knum % $tlen};
        $nh1 = strpos($chars, $ch1);
        $txt = substr_replace($txt, '', $knum % $tlen--, 1);
        $ch2 = $txt{$nh1 % $tlen};
        $nh2 = strpos($chars, $ch2);
        $txt = substr_replace($txt, '', $nh1 % $tlen--, 1);
        $ch3 = $txt{$nh2 % $tlen};
        $nh3 = strpos($chars, $ch3);
        $txt = substr_replace($txt, '', $nh2 % $tlen--, 1);
        $nhnum = $nh1 + $nh2 + $nh3;
        $mdKey = substr(md5(md5(md5($key . $ch1) . $ch2 . $ikey) . $ch3), $nhnum % 8, $knum % 8 + 16);
        $tmp = '';
        $j = 0;
        $k = 0;
        $tlen = strlen($txt);
        $klen = strlen($mdKey);
        for ($i = 0; $i < $tlen; $i++) {
            $k = $k == $klen ? 0 : $k;
            $j = strpos($chars, $txt{$i}) - $nhnum - ord($mdKey{$k++});
            while ($j < 0) $j += 63;
            $tmp .= $chars{$j};
        }
        $tmp = str_replace(array('-', '_', '.'), array('+', '/', '='), $tmp);
        return trim(base64_decode($tmp));
    }
}